Помогите, пожалуйста 1) 2cos^2 a = 1 + -/2 – cos 2x 2) cos^2 6x + sin^2 3x – 1 = 0

2) sin^2 3x = 1 – cos^2 6x

sin^2 6x – sin^2 3x = 0

4sin^2 3x * cos^2 3x – sin^2 3x = 0

sin^2 3x*(4cos^2 3x - 1) = 0

<span>sin^2 3x = 0    cos^2 3x =1/4</span>

По формулам понижения степени:

<span>(1 - cos 6x)/2 = 0              (1 + cos 6x)/2 = ¼</span>

<span>co6x = 1                             cos6x = - ½</span>

<span>x = pi/3 * n                        6x = </span>±(2pi/3) +2pi n

<span>                                              x = </span>±<span>pi/4 + pi/3 *n</span>